TMS320F28235-Q1: GPIO register read incorrect value

Hi,

These days we faced one issue from F28235.

GPIO 32 and 33 are used for I2C. After these code execution, we found that:

1. GPBQSEL1 bit 2 is still 0, instead of 1; bit 3 is 1, which is correct;
2. GPBMUX1 bit 2 is still 0, instead of 1; bit 0 is 1, which is correct.

EALLOW;

    GpioCtrlRegs.GPBQSEL1.bit.GPIO32 = 3;  // Asynch input GPIO32 (SDAA) (bit 1 and 0)

GpioCtrlRegs.GPBQSEL1.bit.GPIO33 = 3;  // Asynch input GPIO33 (SCLA) (bit 3 and 2)

    GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 1;   // Configure GPIO32 to SDAA  (bit 1 and 0)

GpioCtrlRegs.GPBMUX1.bit.GPIO33 = 1;   // Configure GPIO33 to SCLA   (bit 3 and 2)

EDIS;

These tests were done:

1. GPBQSEL1 and GPBMUX1 register values are read from JTAG and register address, they are the same;
2. After writing “1” and “3”, although incorrect read value, I2C functions are OK. It means that, “GpioCtrlRegs.GPBMUX1.bit.GPIO33” shows in expression window with value “0”, but the GPIO works as I2C function.
3. Another pcs of F28235 was checked. There’ s no this kind of issue.

My doubt is: what could be the issue? How can we progress?

Thanks a lot.

Br, Jordan